Air release coefficient 3

[Dave2614]

What is the typical/average air release coefficient of a PRV on an oil/gas production slop tank.

 

[Latexman]

Liquid, vapor, or 2 phase release?

Good luck,
Latexman

 

[Dave2614]

To Latexman: Vapor

Thank you very much.

 

[Latexman]

0.95

Good luck,
Latexman

 

[Dave2614]

I have just learned that the PSV was a 3" Varec valve. I do not tknow the size of the orifice. Would that help in determining the amount of gas/vapor that can release through it?

 

[CMA010]

The size will be 3". To avoid any confusion, you say it's a varec so you're talking about low pressure applications here (e.g. breather valves)? For low pressure applications the 0.95 is not valid.

You can look at the Tyco/Varec website for flowcurves or you can contact your local Varec supplier for information about the capacity of the valve. You need to know the valve type and the allowable overpressure.

 

[stookeyfpe]

If it is an atmospheric tank you also need to ensure the pressure relief device complies with NFPA 30.

Calculations will be based on the surface area of the tank.

Have fun,

Old white headed guy

 

[Latexman]

CMA010 is right, the 0.95 is not used for a low pressure device. Seek out the vendor's flow curves. Earlier, I thought you had a pressure vessel with a conventional safety valve on it. Sorry!

Good luck,
Latexman

 

[Dave2614]

Thanks guys for all of your help. I just contacted Varec to get the flow curve on the valve. Unfortunately, I do not know the model number and the guy I was speaking with was unable to venture a guess at which valve I was trying to describe. Maybe you guys can venture a guess.

Here is what I recently learned on the valve. It is a Varec valve with a 1" inlet and 2.5" outlet; releases at 8 oz. If anyone could tell me what Model or series this might be, I would greatly appreciate it.

Dave

 

[Latexman]

I thought the smallest unit Varec made was a 2" x 2" (or 2" x 3" in the new style), so I have no idea what you have. Does it have an information tag on it?

Good luck,
Latexman